If any Walgreens customers are hoarding points in the store's loyalty program, it might be time to cash in.

The Deerfield-based drugstore chain is changing the expiration policy on its Balance Rewards points. Starting Aug. 25, points will expire one year after the date they were earned. Previously they expired after three years.

Walgreens spokeswoman Emily Hartwig-Mekstan said in an email that company officials believe the new policy will encourage customers "to redeem their points more frequently and lead to more engagement with the program."

Additionally, the shorter expiration window is consistent with other retailer loyalty reward programs, she said.

Members of the Starbucks Rewards program, for example, receive benefits based on the number of "stars" they earn through purchases. A member must earn at least one star each year after enrolling to receive benefits of the program's most basic level, and stars expire after six months.

Having points expire after three years is a model better suited for travel-related loyalty programs, like airline points, said Melissa Fruend, partner at Toronto-based consulting firm LoyaltyOne Global Solutions.

"I don't think Walgreens is the type of retailer where you want to save up and splurge," she said. "I would be shocked if somebody (wasn't) able to redeem a dollar within a year."

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Walgreen's Balance Rewards program launched in 2012. Critics at the time argued that it was late to the game, falling behind rivals Rite Aid, which already had a well-established program at the time, and CVS, which launched its ExtraCare card nationally in 2001.

As of August 2016, Walgreen's Balance Rewards program had 87 million active members, Hartwig-Mekstan said.

Here's how the program works: Members earn 10 points for every $1 spent on almost everything. Items such as alcohol are excluded, and the point structure is different for prescriptions and immunizations, for example.

Once members earn 1,000 points, they can get $1 off. That scales up: 3,000 points is $3 off, and 10,000 points is $10 off.

The discount isn't automatically activated at checkout, Hartwig-Mekstan said. A cashier might ask customers if they want to redeem or the PIN pad can prompt it as well.

Additionally, customers should be vigilant in asking cashiers what they can redeem, Fruend said — just in case.

"A lot of them are part-time workers and that's not necessarily the top thing on their mind," she said.